Light pollution may promote the spread of West Nile virus

From Science News
January 9, 2018

SAN FRANCISCO, CALIFORNIA—After the West Nile virus appeared on the U.S. East Coast in 1999, it spread across the entire country in just a few years, sickening thousands of people and striking down whole flocks of robins, crows, and other birds. Now, a new study suggests the mosquito-borne virus may have had an unexpected helper: light pollution. Birds infected with West Nile can spread the virus twice as long when they are exposed to night light, according to a study presented here over the weekend at the annual meeting of the Society for Integrative and Comparative Biology.

The work “shows that light pollution is not only bad for our [daily rhythms], but also can affect disease prevalence and transmission,” says Jenny Ouyang, an integrative physiologist at the University of Nevada in Reno. “Perhaps infection in humans and other animals is also affected by light,” adds Yale University epidemiologist Durland Fish. (Neither Ouyang nor Fish were involved in the study.)

West Nile is primarily a bird virus, but people occasionally get infected because some bird-biting mosquitoes dine on human blood as well. Human infections can cause fevers, body aches, rashes, diarrhea, long-term fatigue, and, in some cases, inflammation of the brain and its membranes. In the United States, almost 2000 people have died from West Nile since its arrival.

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